The present invention relates generally to dispensers and more particularly to devices for co-dispensing two or more substances which mixed together form an amalgamated product.
Devices for dispensing substances, or dispensers, are well known and widely used in the art.
Devices adapted to co-dispense two or more substances which mix together to form an amalgamated product are well known in the art. Such devices are widely used in numerous commercial applications, such as in the dispensing of cosmetic, food or drink products. Devices adapted to co-dispense two or more substances are typically constructed to dispense the amalgamated product in a single, fixed, ratio between the two or more constituent substances. However, it has found to be desirable in certain applications to vary the ratio of the constituent substances which make up the amalgamated composition.
Accordingly, devices having multiple chambers for holding different flowable substances which allow for the selectable adjustment of the relative concentration of the substances dispensed thereby have been conceived in several different forms.
As an example, in U.S. Pat. No. 5,568,883 to R. J. Cataneo et al., there is disclosed an apparatus for dispensing two flowable substances in a user-selectable ratio. The dispensing apparatus includes first and second containers for receiving flowable substances. Each container has a dispensing end and a second end which initially includes a piston, which is movable only toward the dispensing end as the substances are dispensed. The dispensing apparatus also includes a manifold member having an inlet with a pair of inlet openings for removably receiving the containers. The manifold member is internally divided into two chambers for receiving the respective flowable substances. A pump member, which is movable with respect to the manifold chamber, having an inlet end in fluid communication with the manifold chambers is provided. A selector member with a single opening is provided in fluid communication with the outlet end of the manifold member. Upon movement of the pump member by a user in a first direction from its initial position with respect to the manifold member, a predetermined measure of flowable substance is dispensed from the apparatus. The ratio of the dispensed substances is user variable from 100% of the first flowable substance and 0% of the second flowable substance when the selector member is in the first position, to 0% of the first flowable substance and 100% of the second flowable substance when the selector member is in the second position, to any desired ratio therebetween when the selector member is in an intermediate position.
As another example, in U.S. Pat. No. 5,947,335 to R. J. Milio et al., there is disclosed a dispenser having at least two compartments wherein the amount of product dispensed from at least one of the compartments can be adjusted prior to dispensing. Advantageously, products in both compartments are dispensed using the same actuator. Different volumes of product can be dispensed from at least one of the chambers even though the volume of product dispensed from the other chamber need not be varied and even though the same actuator may be used to effect the dispensing of product.
It has been found that conventional devices for co-dispensing two or more substances in a user adjustable ratio typically suffer from one or more notable design flaws that impair or detract from the functionality of the product to accurately dispense the desired quantities of the constituent substances which form the amalgamated product.
As an example, it has been found that certain prior art devices which co-dispense two or more substances in a user adjustable ratio often inaccurately dispense the desired quantities of the constituent substances which form the amalgamated product due to inconsistencies in energy transmission. Specifically, conventional devices for co-dispensing two or more substances which utilize a multi-chamber squeeze-type bottle require the user to apply a constant and equal amount of pressure to each chamber of the dispenser throughout the application of pressure in order to ensure the proper consistency of the amalgamated product. As can be appreciated, if the user applies an inconsistent amount of pressure on the device, the relative quantities of the constituent substances delivered will vary, thereby producing an amalgamated product having an inaccurate proportion of its constituent substances.
As another example, it has been found that certain prior art devices which co-dispense two or more substances in a user adjustable ratio often inaccurately dispense the desired quantities of the constituent substances which form the amalgamated product due to dissimilarities in the viscosities of the constituent substances. Specifically, conventional devices for co-dispensing two or more substances which utilize a single pump mechanism to draw multiple constituent substances of dissimilar viscosities will preferentially draw more of the lower viscosity substance than the higher viscosity substance, thereby producing an amalgamated product having an inaccurate proportion of its constituent substances.
As another example, it has been found that certain prior art devices which co-dispense two or more substances in a user adjustable ratio often inaccurately dispense the desired quantities of the constituent substances which form the amalgamated product due to individual variances in the viscosity of each constituent substance. Specifically, conventional devices for co-dispensing two or more substances in a user adjustable ratio will often experience changes in the viscosity of each constituent substance over time due to changes in environmental conditions, such as temperature, pressure or humidity. As a consequence, the change in the viscosity of each constituent substance will cause the device to preferentially draw more of the lower viscosity substance than the higher viscosity substance, thereby producing an amalgamated product having an inaccurate proportion of its constituent substance. It should be noted that problems associated with the changes in the viscosity of each constituent substance is particularly relevant when dispensing suntan lotion because the amalgamated product is often dispensed while exposed to a relatively cool environment (i.e., within an air conditioned building having a temperature of 68.degree. Fahrenheit) and a relatively hot environment (i.e., on a beach having a temperature reaching 100.degree. Fahrenheit), thereby exposing the product to a significantly large range of operating temperatures.
As another example, it has been found that certain prior art devices which co-dispense two or more substances in a user adjustable ratio often inaccurately dispense the desired quantities of the constituent substances which form the amalgamated product due to system lag in the dispenser. Specifically, conventional devices for co-dispensing two or more substances in a user adjustable ratio are often constructed to include a baffling chamber located between the metering assembly and the dispenser outlet, the baffling chamber serving as a compartment in which the multiple solutions mix to form the desired amalgamated product. In use, remnants of the mixed product often lag within the baffling chamber and can compromise the accuracy of the relative quantities of the constituent substances in future mixtures. As a result, in order to accurately dispense a mixed product in a user-selectable ratio, the lagging contents must be completely emptied from the baffling chamber before forming the amalgamated product in its intended ratio.
As another example, it has been found that certain prior art devices which co-dispense two or more substances in a user adjustable ratio often inaccurately dispense the desired quantities of the constituent substances which form the amalgamated product due to variable back pressure in the dispenser. Specifically, conventional devices for co-dispensing two or more substances which include a selector dial for adjusting the ratio of the constituent flowable substances which are mixed within a baffling chamber will often experience a resistance to flow , or back pressure, exerted by the mixture in the chamber which will vary depending upon the setting of the selector dial and the composition of the resulting mixture in the chamber. As a result, the composition of the amalgamated mixture, which is created by mechanisms that depend upon a known resistance to flow downstream of a pump mechanism will vary as a function of the mixture from the previous dispensing cycle, thereby creating a mixture of substances in an inaccurate ratio.
In addition to the design flaws noted above that impair the ability of a dispenser to accurately dispense the desired quantities of the constituent substances which form the amalgamated product, certain prior art devices which co-dispense two or more substances in a user adjustable ratio suffer from additional drawbacks.
As an example, it has been found that certain prior art devices which co-dispense two or more substances in a user adjustable ratio are mechanically complicated in nature. Specifically, conventional devices for co-dispensing two or more substances in a user adjustable ratio often utilize an internal diaphragm to create multiple internal chambers for the substances, thereby creating a relatively complex device which requires a considerable number of parts. Due to its considerable complexity, such a device is relatively difficult and costly to manufacture.
As another example, it has been found that certain prior art devices which co-dispense two or more substances in a user adjustable ratio are often difficult to use. Specifically, conventional devices for co-dispensing two or more substances in a user adjustable ratio are not typically designed to be operated with one hand. To the contrary, conventional devices for co-dispensing two or more substances in a user adjustable ratio often require that the dispenser be placed on a table or other firm horizontal surface to counteract the forces needed to actuate the dispenser. In this manner, one hand is typically used to actuate the dispenser and the other hand is used to receive the amalgamated mixture. As a result, because the user is precluded from holding the dispenser in one hand and ejecting the amalgamated mixture into the other, the device can not be used in those situations in which the consumer does not have access to a firm support surface, such as while dispensing suntan lotion on the beach.